Core language and framework features, Rails 8.1 updates, Ruby 3.4 improvements
LEFT JOIN queries often break the moment you add a WHERE on the joined table—silently turning into INNER JOIN behavior. Learn the correct Rails patterns (ON vs WHERE, scoped associations, where.missing/where.associated, EXISTS) and how to verify generated SQL.
Ruby 4.0.0 is released (Dec 25, 2025). For Rails apps, the real risks are stdlib gem changes (CGI), Net::HTTP behavior shifts, and Bundler 4. Here’s what breaks first, how to fix safely, and what Ruby 4 performance does—and doesn’t—solve.
Copied SQL into Rails and still got N+1? Rewrote in ActiveRecord and still got N+1? The fix is a set-based mental model: where N+1 really comes from, how to verify it, and the AR patterns that eliminate it safely.
If you know SQL, ActiveRecord can feel pointless—until it saves you from consistency bugs. Here’s the mental model: where SQL alone breaks app invariants, and how to use AR without losing performance.
A production-minded guide to building a modular monolith in Rails using Engines: where boundaries usually leak, how to structure code, and the upgrade-safe patterns that prevent cross-domain coupling.
A production-minded Rails 8.1 devcontainer setup that standardizes Ruby, Node, Postgres, and tooling across a team—plus the real failure modes and how to avoid them.
Ruby 3.5 was released as a preview; Ruby 4.0 shipped. Here’s what actually matters for Rails apps: what won’t change, what can break, and where SQL/ActiveRecord fixes beat runtime upgrades.
A production-focused preview of Rails 8.2 explaining real-world impact on caching, TypeScript integration, Turbo behavior, and upgrade risks.